CURRENT RATINGS XLPE CABLE

CURRENT RATING (XLPE)

Basic assumption and conditions of installation :

  • Max. conductor temperature at continuous operation 90C
  • Ambient Air temperature 40C
  • Ground temperature 30C
  • Thermal resistively of soil 150C Cm/W
  • Depth of laying 750mm
  • Max. conductor temperature for short circuit 250C

Rating factors for variation in ground temperature :

Ground temperature C 15 20 25 30 35 40
Rating factor 1.12 1.08 1.03 1.00 0.96 0.91

Rating factors for variation in Ambient Air Temperature

Ground temperature C 25 30 35 40 45 50
Rating factor 1.14 1.10 1.04 1.00 0.95 0.90

Rating factors cables laid directly in ground in horizontal formation

No. of cables Distance of cables
  Touching 15cm 30cm 45 cm
2 0.79 0.82 0.87 0.90
3 0.69 0.75 0.79 0.83
4 0.62 0.69 0.74 0.79
5 0.58 0.65 0.72 0.76
6 0.54 0.61 0.69 0.75

Rating factor for variation in depth of laying in ground

Depth of laying Size
  Upto 25 mm2 25 to 300 mm2 Above 300 mm2
75cm 1.00 1.00 1.00
90cm 0.99 0.98 0.97
105cm 0.98 0.97 0.96
120cm 0.97 0.96 0.95
150cm 0.96 0.94 0.92
180cm 0.95 0.93 0.91